German Published Patent Application No. 39 18 769 A1 describes a semiconductor chip with an elastically deformable diaphragm formed therein for use in a pressure sensor. Under the influence of pressure or pressure changes, the diaphragm is deformed together with piezosensitive resistance zones in the region of the diaphragm. As a result, the piezosensitive resistance zones supply corresponding electrical signals to evaluation circuits. Such a sensor, however, can be used only in media which do not attack the silicon material. If such a sensor is introduced, for example, into acids or lyes, then the diaphragm of the silicon sensor could be etched or etched through, with the result that the diaphragm's mechanical properties are altered, thus resulting in false measured values or even complete destruction of the diaphragm.